Who dat? David Letterman went for a run on Tuesday, March 22, in St. Bart's, where he was photographed looking completely unrecognizable.

The former CBS Late Show host, 68, who said farewell to his long-running gig in May 2015, stepped out for his jog sporting a bushy white Santa Claus-inspired beard and mustache. His once-golden, full head of hair was also gone, as were his beloved bifocals.

Despite his new look, Letterman seemed as if he was in good spirits as he got his exercise in. The legendary talk show host, clad in a Ball State T-shirt and yellow shorts, grinned at the camera while navigating his way up and down the dirt paths of the posh Caribbean destination.

Letterman's transformation, however, has been in the works since he handed the baton to comedian Stephen Colbert last spring. In September, the star was spotted in NYC sporting the same beard, but seemingly looked more like himself with his glasses on.

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